U.S. patent number 8,661,753 [Application Number 12/882,793] was granted by the patent office on 2014-03-04 for water-resistant apparatuses for photovoltaic modules.
This patent grant is currently assigned to SunPower Corporation. The grantee listed for this patent is Carl J. S. Lenox. Invention is credited to Carl J. S. Lenox.
United States Patent |
8,661,753 |
Lenox |
March 4, 2014 |
Water-resistant apparatuses for photovoltaic modules
Abstract
A water-resistant apparatus is provided. This water-resistant
apparatus is positioned near a photovoltaic module. The
water-resistant apparatus includes hollow, elongated conduits, and
each conduit can hold water with surface tension based on exposure
of the conduit to water. The surface tension causes a formation of
a meniscus that inhibits a flow of water through the conduit.
Inventors: |
Lenox; Carl J. S. (Oakland,
CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Lenox; Carl J. S. |
Oakland |
CA |
US |
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Assignee: |
SunPower Corporation (San Jose,
CA)
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Family
ID: |
43991926 |
Appl.
No.: |
12/882,793 |
Filed: |
September 15, 2010 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20110113704 A1 |
May 19, 2011 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61261730 |
Nov 16, 2009 |
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Current U.S.
Class: |
52/302.1;
454/367; 52/302.3; 454/366; 52/173.3 |
Current CPC
Class: |
F24S
40/40 (20180501); H02S 20/23 (20141201); Y02E
10/50 (20130101); F24S 2020/13 (20180501); Y02B
10/10 (20130101); Y02E 10/40 (20130101) |
Current International
Class: |
E04D
13/143 (20060101); E04D 13/18 (20060101); E04D
13/17 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO-01/90614 |
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Nov 2001 |
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WO |
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WO-2006/028698 |
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Mar 2006 |
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WO |
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WO 2008/153936 |
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Dec 2008 |
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WO |
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Other References
"International Application Serial No. PCT/US2010/048953, Search
Report and Written Opinion mailed Nov. 15, 2010", 19 pgs. cited by
applicant .
International Search Report and Written Opinion in PCT Application
PCT/US2010/051769, mailed Nov. 29, 2010. cited by
applicant.
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Primary Examiner: A; Phi
Attorney, Agent or Firm: Knobbe Martens Olson & Bear
LLP
Government Interests
STATEMENT REGARDING STATE SPONSORED RESEARCH OR DEVELOPMENT
The invention was made with State of California support under
California Energy Commission Contract Number 500-04-009. The Energy
Commission has Certain Rights to this Invention.
Parent Case Text
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application
No. 61/261,730, entitled "Roof Coverings," filed Nov. 16, 2009, the
disclosure of which is incorporated herein by reference.
Claims
What is claimed is:
1. A system of a plurality of photovoltaic modules, the system
comprising: a first photovoltaic module disposed above a sloped
roof, the first photovoltaic module having a top surface configured
to face the sun; a second photovoltaic module disposed above the
sloped roof, the second photovoltaic module having a top surface
configured to face the sun and a bottom surface opposite the top
surface, the second photovoltaic module disposed above and
overlapping a portion of the first photovoltaic module such that at
least a portion of the bottom surface of the second photovoltaic
module is above at least a portion of the top surface of the first
photovoltaic module, the disposition forming a gap between the top
surface of the first photovoltaic module and the bottom surface of
the second photovoltaic modules along the overlapping portion of
the first photovoltaic module; and a water-resistant apparatus
fitted within the gap, the water-resistant apparatus comprising a
plurality of hollow, elongated conduits extending through the gap
wherein each conduit is configured to hold water with surface
tension based on exposure of each conduit to the water, with the
surface tension causing a formation of a meniscus that inhibits a
flow of water through each conduit and onto the sloped roof.
2. The system of claim 1, wherein the meniscus formed within the
each conduit completely blocks an opening within the each
conduit.
3. The system of claim 1, wherein the each conduit has an opening
with a diameter between about 0.1 inches and about 0.4 inches.
4. The system of claim 1, wherein the plurality of hollow,
elongated conduits comprises a plurality of cylindrical tubes.
5. The system of claim 1, wherein the plurality of hollow,
elongated conduits comprises a plurality of rectangular tubes.
6. The system of claim 1, wherein the plurality of hollow,
elongated conduits comprises a plurality of hexagonal tubes.
7. The system of claim 1, wherein the plurality of hollow,
elongated conduits is formed from a plurality of fluted, corrugated
sheets.
8. The system of claim 1, wherein each conduit has an opening that
is dimensioned to accommodate the formation of the meniscus based
on the exposure of each conduit to the water.
9. The system of claim 1, wherein a space is formed between the
sloped roof and the first and second photovoltaic modules; and
wherein each conduit is configured to convey a flow of air into and
out from the space in an equalization between a pressure associated
with the space and an atmospheric pressure.
10. The system of claim 1, wherein each conduit has an axis,
wherein the first photovoltaic module has a sun-facing surface, and
wherein the axis is aligned substantially parallel to the
sun-facing surface.
11. The system of claim 1, wherein each conduit has an axis,
wherein the first photovoltaic module has a sun-facing surface; and
wherein the axis is aligned less than about 80 degrees in reference
to the sun-facing surface.
12. The system of claim 1, wherein the first photovoltaic module
comprises a channel located along the overlapping portion and
proximate to the water-resistant apparatus, with the channel
configured to collect water that flows through the plurality of
hollow, elongated conduits.
Description
FIELD
The present disclosure relates generally to photovoltaic modules.
In an embodiment, the disclosure relates to water-resistant
apparatuses for photovoltaic modules.
BACKGROUND
Photovoltaic modules can be secured to roofs, but the modules must
be designed and mounted in such a way that they can withstand
sufficiently high wind speeds. Furthermore, water can penetrate
between the photovoltaic modules and, for example, corrode the
mounts that secure the photovoltaic modules to the roofs. One
traditional technique to waterproof an array of photovoltaic
modules is to fit covers over spaces between the photovoltaic
modules to prevent water from penetrating through these spaces.
However, many of these coverings cause pressure differences between
a cavity underneath the photovoltaic modules and the atmosphere. As
a result of the pressure difference, high winds can more easily
dislodge the photovoltaic modules from the roof and accordingly,
the mounts and/or the photovoltaic modules for use on roofs need to
be designed to be stronger and heavier to accommodate the extra
forces created by the pressure difference.
SUMMARY
In an embodiment, a water-resistant apparatus is provided. This
water-resistant apparatus is positioned near a photovoltaic module.
The water-resistant apparatus includes hollow, elongated conduits,
and each conduit can hold water with surface tension based on
exposure of the conduit to water. The surface tension causes a
formation of a meniscus that inhibits a flow of water through the
conduit.
In another embodiment, a photovoltaic module is provided. This
photovoltaic module has a surface bound by an edge and includes a
water-resistant apparatus coupled to this surface and located along
this edge. The water-resistant apparatus includes hollow, elongated
conduits, and each conduit holds water with surface tension based
on exposure of the conduit to water. Again, the surface tension
causes a formation of a meniscus that inhibits a flow of water
through the conduit.
In yet another embodiment, a system of a plurality of photovoltaic
modules is provided. This system includes a first photovoltaic
module and a second photovoltaic module disposed above and
overlapping a portion of the first photovoltaic module. This
disposition forms a gap between the first and second photovoltaic
modules along the portion of the first photovoltaic module. A
water-resistant apparatus is fitted within the gap, and this
water-resistant apparatus includes hollow, elongated conduits.
BRIEF DESCRIPTION OF DRAWINGS
The present disclosure is illustrated by way of example and not
limitation in the figures of the accompanying drawings, in which
like references indicate similar elements and in which:
FIG. 1 depicts an array or system of photovoltaic modules mounted
on a roof;
FIG. 2 depicts a side view of an array of photovoltaic modules
mounted on the roof;
FIG. 3A depicts a three-dimensional view of an embodiment of a
water-resistant apparatus;
FIG. 3B depicts a sectional view of the water-resistant apparatus
along a cut plane A-A depicted in FIG. 3A;
FIGS. 4A, 4B, 4C, and 4D depict various embodiments of
water-resistant apparatuses;
FIGS. 5A and 5B depict side views of two different embodiments of
water-resistant apparatuses;
FIG. 6 depicts the use of the water-resistant apparatuses for
pressure equalization in a system of photovoltaic modules;
FIGS. 7A, 7B, and 7C depict various embodiments of photovoltaic
modules with attached water-resistant apparatuses;
FIG. 8 depicts a side view of a system of photovoltaic modules
mounted on a sloped roof, consistent with yet another embodiment of
the present invention; and
FIG. 9 depicts a three-dimensional view of a photovoltaic module
having both a channel and a water-resistant apparatus, consistent
with yet another embodiment of the present invention.
DETAILED DESCRIPTION
The following description and the drawings illustrate specific
embodiments of the invention sufficiently to enable those skilled
in the art to practice them. Other embodiments can incorporate
structural, logical, electrical, process, and other changes.
Examples merely typify possible variations. Individual components
and functions are optional unless explicitly required, and the
sequence of operations can vary. Portions and features of some
embodiments can be included in or substituted for those of others.
Embodiments of the invention set forth in the claims encompass all
available equivalents of those claims. Embodiments of the invention
can be referred to, individually or collectively, herein by the
term "invention" merely for convenience and without intending to
limit the scope of this application to any single invention or
inventive concept if more than one is in fact disclosed.
A photovoltaic module is a packaged interconnected assembly of
solar cells (or photovoltaic cells), and FIG. 1 depicts an array or
system of photovoltaic modules 104 mounted on a roof 102. In this
example, the photovoltaic modules 104 are secured to the roof 102
with rack systems that include vertical stanchions and lateral
rails 106. In a rainstorm, the photovoltaic modules 104 shield the
roof 102 from exposure to water. However, water can penetrate
through gaps between the photovoltaic modules 104. For example,
instead of falling directly onto the sun-facing surfaces of the
photovoltaic modules 104, rain can be blown laterally in a
rainstorm such that it enters through gaps between the overlapping
edges of the photovoltaic modules 104.
Embodiments of the present invention describe the use of examples
of different water-resistant apparatus to waterproof the
photovoltaic modules 104. FIG. 2 depicts a side view of an array of
photovoltaic modules 104 and 104' mounted on the roof 102,
consistent with an embodiment of the present invention. Again, the
photovoltaic modules 104 and 104' are secured to the roof 102 with
rack systems that include vertical stanchions 204 and lateral rails
106.
In this example, the photovoltaic module 104 is located above and
overlaps a portion of the photovoltaic module 104', so that an edge
of the module 104 is located beyond and at the edge of module 104',
when seen in top view. This overlap and vertical spacing results in
a gap between the photovoltaic modules 104 and 104'. In the
embodiment depicted in FIG. 2, a water-resistant apparatus 202 is
positioned in the gap between the photovoltaic modules 104 and 104'
to inhibit water from penetrating the gap. As explained in more
detail below, the water-resistant apparatus 202 can inhibit water
penetration through use of hollow, elongated conduits.
FIG. 3A depicts a three-dimensional view of an embodiment of a
water-resistant apparatus 202. The water-resistant apparatus 202 is
composed of rows of hollow, elongated conduits that are vertically
stacked on top of each other and extend through the apparatus 202
in a direction transverse to a length l of the apparatus 202. As
used herein, a "hollow, elongated conduit" refers to a hollow,
enclosed structure having openings at two ends for conveying liquid
and/or air.
The water-resistant apparatus 202 has a length l, height h, and
depth d. The height h can be of any suitable height. In one
embodiment, the water-resistant apparatus 202 is fitted within a
gap formed between photovoltaic modules or between a photovoltaic
module and some type of surface, and therefore, the length l and
height h can be dimensioned to fit within the gap. Given that the
water-resistant apparatus 202 can be fitted along an edge of a
photovoltaic module, the depth d can span a length of such an edge.
However, it should be appreciated that the length l is at least
greater than a diameter of a hollow, elongated conduit. Since many
photovoltaic modules have edges that are much longer than a height
of the gap, the water-resistant apparatus 202 depicted in FIG. 3A
is shaped like a rectangular bar. However, in other embodiments,
the water-resistant apparatus 202 can have a variety of other
different shapes. For example, in an alternate embodiment, the
water-resistant apparatus 202 can be shaped as a cube. In yet
another embodiment, the water-resistant apparatus 202 can be shaped
as a cylinder.
FIG. 3B depicts a sectional view of the water-resistant apparatus
202 along a cut plane A-A depicted in FIG. 3A. The water-resistant
apparatus 202 includes vertically stacked rows of hollow, elongated
conduits 302. The conduits 302 are shaped and dimensioned to hold
water with surface tension within the conduits 302 when the
conduits 302 are exposed to water. It should be noted that the
terms "hollow, elongated conduit" and "conduit" can be used
interchangeably. As depicted in FIG. 3B, the surface tension within
the conduits 302 causes formations of menisci 304 that inhibit
further flow of water through the conduits 302. In other words, the
menisci 304 formed within the conduits 302 completely block the
openings within the conduits 302 and therefore, can inhibit or
completely prevent additional water from flowing through the
conduits 302.
Each conduit 302 defines an internal void, passage, or opening,
which is dimensioned such that it accommodates the formation of a
meniscus 304 when exposed to water. In one embodiment, a conduit
302 can have an opening having a constant cross-sectional outline
and having a maximum cross-sectional dimension (e.g., a diameter)
of between about 0.1 inches (2.54 mm) and about 0.4 inches (10.16
mm). A "diameter," as used herein, refers to a straight line
connecting the center of any suitable geometric figure with two
points on the perimeter or surface. As used herein, the term
"about" means that the specified dimension or parameter can be
varied within an acceptable manufacturing tolerance for a given
application. In some embodiments, the acceptable manufacturing
tolerance is .+-.10%.
FIGS. 4A, 4B, 4C, and 4D depict various embodiments of
water-resistant apparatuses 202. It should be appreciated that the
hollow, elongated conduits can have a variety of different shapes.
For example, FIG. 4A depicts a front view of an embodiment of a
water-resistant apparatus composed of vertically stacked
cylindrical tubes. Here, each cylindrical tube can have a diameter
402 between about 0.1 inches and about 0.4 inches. FIG. 4B depicts
a front view of a different embodiment of a water-resistant
apparatus 202 composed of vertically stacked hexagonal tubes. Here,
each hexagon tube can have a longest diameter 404 (or a maximum
cross-sectional dimension) between about 0.1 and about 0.4 inches.
FIG. 4C depicts a front view of another embodiment of a
water-resistant apparatus 202 composed of vertically stacked
rectangular tubes. In this embodiment, each rectangular tube 406
can have a side length between about 0.1 inches and about 0.4
inches. FIG. 4D depicts yet another embodiment of a water-resistant
apparatus 202 composed of conduits formed from fluted, corrugated
sheets. Again, in this embodiment, the longest diameter 408 of each
conduit can be between about 0.1 and about 0.4 inches.
FIGS. 5A and 5B depict side views of two different embodiments of
water-resistant apparatuses 202. The water-resistant apparatuses
202 are composed of vertically stacked conduits 302 and each
conduit 302 has an axis (e.g., axes 502 and 502') aligned along a
length of the conduit 302. As depicted, both water-resistant
apparatuses 202 are placed relative to a surface of a photovoltaic
module 104. The surface can be a sun-facing surface or a surface
that is opposite to the sun-facing surface, which is referred to as
a "non sun-facing surface."
In the embodiment depicted in FIG. 5A, the conduits 302 are aligned
such that their axes 502 are substantially parallel to the surface
of the photovoltaic module 104. In the other embodiment depicted in
FIG. 5B, the conduits 302 are aligned such that their axes 502' are
aligned to be less than about 80.degree. in reference to the
surface. The sloped alignment of the conduits 302 can possibly
further enhance the water-resistant properties of the
water-resistant apparatus 202 because the flow water has to travel
upwards, which is against gravity.
FIG. 6 depicts the use of the water-resistant apparatuses 202 for
pressure equalization in a system of photovoltaic modules 104. The
system 600 includes multiple photovoltaic modules 104 stacked on
top of each other and mounted on a sloped roof 102. Fitted within
the gaps between the photovoltaic modules 104 are water-resistant
apparatuses 202, as described above. As depicted, a space 604 or
cavity is formed between the sloped roof 102 and the photovoltaic
modules 104. It should be appreciated that this space 604 can be at
a different pressure than atmospheric pressure 602. For example, a
temperature difference between the space 604 and areas outside the
space 604 can cause a pressure difference. If the pressure in space
604 is not equal to atmospheric pressure, the pressure difference
can generate lift on the photovoltaic modules 104, thereby possibly
dislodging the photovoltaic modules 104 from the sloped roof
102.
However, the conduits within the water-resistant apparatus 202 are
hollow and therefore, the conduits can convey a flow of air either
into or out from the space 604 such that the pressure in the space
604 equalize with atmospheric pressure 602. For example, if the
pressure in space 604 is higher than atmospheric pressure, then the
pressure can force air within space 604 to flow out of the conduits
such that the pressure equalizes with atmospheric pressure 602. In
another example, if the atmospheric pressure in space 604 is lower
than atmospheric pressure 602, then atmospheric pressure 602 can
force air from the outside into and through the conduits such that
the pressure in space 604 equalizes with the atmospheric pressure
602.
Even when menisci are formed within the conduits, a sufficient
pressure difference can overcome the blockage created by the
menisci such that a flow of air can be conveyed out from the
water-resistant apparatuses 202 when exposed to water. As a result,
the water-resistant apparatuses 202 are designed to inhibit the
flow of water while at the same time allowing pressure in space 604
to equalize with the atmospheric pressure. The pressure
differentials at any given wind speed can therefore be reduced with
the use of water-resistant apparatuses 202. Accordingly, the
photovoltaic modules 104 and/or mounts can be designed to be
lighter and less durable.
FIGS. 7A, 7B, and 7C depict various embodiments of photovoltaic
modules 104 with attached water-resistant apparatuses 202. As
depicted in FIG. 7A, the photovoltaic module 104 has a leading edge
702, a trailing edge 706, and side edges 708. A leading edge 702
(or "head lap") is a forward edge of the photovoltaic module 104
that faces a drip edge of a roof. The trailing edge 706 is an edge
opposite to the leading edge 702 and, for example, can face a ridge
of a sloped roof. The side edges 708 are edges that connect to both
the leading edge 702 and the trailing edge 706.
In one embodiment, as depicted in FIG. 7A, the water-resistant
apparatus 202 is attached to a non sun-facing surface of the
photovoltaic module 104 and is located along the leading edge 702
of the photovoltaic module 104. In the alternative embodiment
depicted in FIG. 7B, the water-resistant apparatus 202 is attached
to a sun-facing surface of the photovoltaic module 104 and is
located along the trailing edge 706 of the photovoltaic module 104.
Additionally, the water-resistant apparatus 202 can also be located
along one or more side edges 708 of the photovoltaic module 104.
For example, as depicted in the embodiment illustrated in FIG. 7C,
the water-resistant apparatus 202 is attached to a non sun-facing
surface and located along one of the side edges 708.
FIG. 8 depicts a side view of a system of photovoltaic modules 104
mounted on a sloped roof 102, consistent with yet another
embodiment of the present invention. The system 800 includes
multiple photovoltaic modules 104 mounted on a sloped roof 102.
Additionally, water-resistant apparatuses 202 and 202' are fitted
within the gaps between the overlap of photovoltaic modules 104 and
104' and between a surface of the sloped roof 102 and the
photovoltaic module 104'. In this embodiment, the photovoltaic
module 104' has a channel 802 located along a trailing edge of the
photovoltaic module 104'. This channel 802 can be cut into a
sun-facing surface of the photovoltaic module 104' and can be
located near the water-resistant apparatus 202. This channel 802
can have a variety of different shapes, such as a half circle, a
rectangle, a triangle, or other suitable shapes.
This channel 802 collects any water that flows through the
water-resistant apparatus 202 and carries the water to a side edge
of the photovoltaic module 104'. As a result, this channel 802 can
further facilitate the waterproofing of a system 800 of
photovoltaic modules 104 and 104' because it minimizes the amount
of water leaked onto the sloped roof 102.
FIG. 9 depicts a three-dimensional view of a photovoltaic module
104 having both a channel 802 and a water-resistant apparatus 202,
consistent with yet another embodiment of the present invention. As
depicted, the photovoltaic module 104 has a water-resistant
apparatus 202 attached to a non sun-facing surface along and near a
leading edge of the photovoltaic module 104. The photovoltaic
module 104 also has a channel 802 located along and near a trailing
edge of the photovoltaic module 104. This channel 802 is cut into
the sun-facing surface and, as discussed above, collects excess
water leaked through another water-resistant apparatus (not shown),
which is located near the channel 802, and carries this water to
the side edges of the photovoltaic module 104. In one example, one
or more of the side edges of the photovoltaic module 104 can be
placed near an edge of the roof such that the channel 802 carries
the water towards the edge and away from a surface of the roof.
Alternatively, the photovoltaic module 104 can be placed such that
its channel 802 connects to another channel (not shown) that
carries water towards an edge of a roof.
In the foregoing detailed description, various features are
occasionally grouped together in a single embodiment for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting an intention that the
claimed embodiments of the subject matter require more features
than are expressly recited in each. Rather, as the following claims
reflect, the invention can lie in less than all features of a
single disclosed embodiment. Thus the following claims are hereby
incorporated into the detailed description, with each claim
standing on its own as a separate preferred embodiment.
Plural instances can be provided for components, operations or
structures described herein as a single instance. Finally,
boundaries between various components, operations, and data stores
are somewhat arbitrary, and particular operations are illustrated
in the context of specific illustrative configurations. Other
allocations of functionality are envisioned and can fall within the
scope of the invention(s). In general, structures and functionality
presented as separate components in the exemplary configurations
can be implemented as a combined structure or component. Similarly,
structures and functionality presented as a single component can be
implemented as separate components. These and other variations,
modifications, additions, and improvements fall within the scope of
the invention(s).
* * * * *